1. Field of the Invention
Embodiments of the invention generally relate to tubing expansion.
2. Description of the Related Art
Methods and apparatus utilized in the oil and gas industry enable placing tubular strings in a borehole and then expanding the circumference of the strings in order increase a fluid path through the tubing and in some cases to line the walls of the borehole. Some of the advantages of expanding tubing in a borehole include relative ease and lower expense of handling smaller diameter tubing and ability to mitigate or eliminate formation of a restriction caused by the tubing thereby enabling techniques that may create a monobore well. Many examples of downhole expansion of tubing exist including patents, such as U.S. Pat. No. 6,457,532, owned by the assignee of the present invention.
However, prior expansion techniques may not be possible or desirable in some applications. Further, issues that present problems with some of these approaches may include ease of makeup at the drill rig floor and operation, ability to transmit torque across an expander tool, and capability to recover a stuck expander tool or insert the tool through restrictions smaller than an expansion diameter. Carrying the expander tool in with unexpanded tubing and fixing the tubing relative to the expander tool can create additional challenges for some applications.
Therefore, there exists a need for improved methods and apparatus for expanding tubing.